Swimming pool filter



United States Patent Inventor Appl. No. Filed Patented SWIMMING POOL FILTER 6 Claims, 8 Drawing Figs.

US. Cl

Int. Cl.

Field of Search References Cited UNITED STATES PATENTS 10/1902 Rudner 210/238 4/1893 Perkins..... 210/238 11/1933 Demers 2l0/48OX 5/1940 Franzmeier. 2l0/480X 3/1965 Bosico 210/169 10/1967 Kraissl, Jr. 210/238 Primary Examiner- Reuben Friedman Assistant Examiner-T. A. Granger Attorney- Leonard H. King ABSTRACT: A sequential filter arrangement consisting of a perforated basket followed by a porous, fibrous material attached to the basket is provided for use with swimming pool PATENTEnnEczelsm I I 3-550 779 IN VENTOR. PETER ALESANDRI'O CA 77mm, Se

41 m M x4 ATTORNEY SWIMMING POOL FILTER This invention relates generally to swimming pools and more particularly to an improved filter arrangement therefor.

BACKGROUND OF THE INVENTION Swimming pools, both the above and below ground types, must be provided with filter means in order to maintain the water free from suspended material. Quite frequently this is a requirement of local ordinances, particularly for relatively large size pools, for example pools having a capacity of two to three thousand gallons and up. A common form of filter medium that is presently being extensively used is diatomaceous earth which is used in conjunction with a-motor-driven pump that extracts water from the pool and passes it through the filter medium before returning the water to the pool. In addition, a relatively coarse filter, such as a perforated basket, is used to remove large size debris such as insects, lint, hair, The perforated filter basket generally is used to skim the debris off the surface of the water whereas the diatomaceous earth is used to filter the main body of the water. Of course, the diatomaceous earth receives all of the water in the pool before recirculating it.

The prior art filtering systems are both costly to use and inconvenient to maintain. The diatomaceous earth must be changed periodically, the intervals between changes depending upon the extent of the usage of the pool and amount of debris carried into the pool by wind, bathers, etc. The purpose of the filter basket is to minimize the need for changing the diatomaceous earth filter by removing as may many large particles of debris as possible. The present invention is directed to means for improving the efficiency of thefiltering system by adding an intermediate, removable, fibrous filter intermediate the filter basket and the diatom aceous earth filter.

Briefly stated, the present invention comprises a porous fibrous material that is conveniently located in the skimmer of the filtering system directly below the filtering basket. The intermediate fibrous filter is preferably washable and may either be made from synthetic or natural fiber material. In order to facilitate cleaning of the intermediate filter, directly filter, means are provided to couple the intermediate filter directly beneath the porous filter basket. Therefore, the water skimmed from the pool will first have the large debris removed by the filter basket and then the water will pass through the intermediate filter to further remove still other debris prior to passing through the diatomaceous earth filter. As will be explained more fully hereinafter, various embodiments incorporating the basic concept of this invention are provided.

Accordingly, it is an important object of this invention to provide an improved filter system for a swimming pool.

It is another object of this invention to provide a filter means intermediate the conventional filter basket and diatomaceous earth filters or the like, used in conventional swimming pools filtering systems.

It is an important object of this invention to provide a filter system for swimming pools, as described above, wherein means are provided for coupling the intermediate filter and the filter basket so that these last two mentioned filter mediums may be removed as a unit.

These and other features, objects and advantages of the invention will, in part, be pointed out with particularity and .will,

in part, become obvious from the following more detailed description of the invention, taken in conjunction with the accompanying drawing forming an integral part thereof.

In the various FIGS. of the drawing like reference characters designate like parts.

I DESCRIPTION OF THE DRAWING FIG. I is a schematic elevational view fragmentarily illustrating a swimming pool using the filter system comprising the present invention;

FIG. 3 is a fragmentary sectional elevational view taken along line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 2 illustrating an alternative embodiment of this invention;

FIG. 5 is a fragmentary sectional elevational view taken along line 5-5 of FIG. 4;

FIG. 6 is a fragmentary elevational view illustrating details of one of the components used in the second embodiment of FIGS. 4 and 5;

FIG. 7 is an exploded perspective view of still another embodiment of the present invention; and

FIG. 8 is an elevational view, partly in section, illustrating the components of the FIG. 7 embodiment in the assembled condition.

Turning now to FIG. I, there is schematically shown the environment of the present invention. A skimmer 10 is suitably mounted in any well-known manner in I a swimming pool designated by a wall member 12. As shown, the skimmer 10 is positioned proximate the water level 14 of the swimming pool 12. The skimmer 10 includes a housing l6 in which suitable openings are provided to permit its usage in a conventional manner. Within the housing 16 of the skimmer 10 there is provided a perforated basket 18, a fibrous filter 20 and coupling means 22 joining the filter basket 18 and the fibrous filter 20 so that both of these last two components may be removed as a unit. Inlet means 24 are also provided in the skimmer 10, the inlet means serving as a main conduit for supplying pool water to the filter 10. Outlet means 26 from the skimmer 10 is in communication with motor-driven pump means 28 and a filter medium such as diatomaceous earth 30, for example, downstream of the pump 28. Conduit 32 provides means for returning the filtered water back to the pool.

It has been found that the diatomaceous earth filter 30 need not be changed as frequently as the intermediate filter 20 which is provided downstream of the filter basket 18 and upstream of the pump 28. Because of this arrangement there will be a substantial saving of the quantity of diatomaceous earth filter that is used. More importantly the apparatus of this invention increases the length of the cycle between changes of the filter media. This provides greater economy as well as more efficient operation. The less frequent change eliminates a bothersome and annoying task. However, merely placing an intermediate filter in the flow path of the water would not be sufficient since from a practical point of view the added filter 20 would not be cleaned frequently enough to be effective unless it was made very convenient to do so. It is to this particular problem of convenience that the present invention is directed.

Turning now to FIGS. 2 and 3, there is shown one embodiment of the present invention. The filter basket 18 is conventional in all respects in that it includes a sidewall 34 and a bottom surface 36. A loop 38 whose function will be described later is formed integrally with the bottom surface 36. Further, the sidewall 34 and the bottom surface 36 include a plurality of perforations 40 that are sized such that they will trap the large debris without materially impeding the flow of water. The intermediate filter 20 comprising the present invention is positioned directly below the filter basket 18 and is comprised of a porous, fibrous material having a higher permeability and a pore size what somewhat larger than the filter medium 30.

The intermediate filter 20 is comprised of a central disclike portion 42, a tubular wall 44 extending upwardly from the disclike portion 42 and a flange 46 extending radially from both the disclike portion 42 and the bottom end of the tubular wall 44. The intermediate fit filter medium 20, as mentioned above, may be either a synthetic or natural fiber material and there is sewn therein, on flange 46, a resilient O-ring 48 to provide some degree of stiffness thereto. Although separate reference characters have been given to the disclike portion 42 an the flange 46, it is apparent that they could be a single unit and the O-ring 48 can be secured proximate the periphery thereof by sewing an annular ring 50 thereon.

There is further provided a patch 52 that is suitably secured such as by sewing, to the center of the disclike portion 42. A

flexible coupling 54, for example, a link chain, is secured at one end thereof to the patch 5 2 and at the other end thereof it is coupled to the loop 38 that is integral with the bottom surface 36 of the filter basket 18. Clip means generally designated by the reference character 56 may be used to removably attach the intermediate filter to the filter basket 18. Thus, it will be seen that when the filter basket is removed to take out the debris that is caught therein the intermediate filter 20 will be removed together therewith. The intermediate filter 20 may then be easily washed by a hose or the like in order to remove any particles that have been trapped therein. it follows that whatever is trapped or caught by the intermediate filter 20 will not reach the diatomaceous earth filter 30 and therefore it will not be necessary to change the diatomaceous earth filter 30 as frequently as has been necessary with prior art filter systems.

FIGS. 4, 5 and 6 illustrate an alternative embodiment of this invention. Where the function and structure is the same as the first embodiment the description thereof will not be repeated. Intermediate filter medium 60 is provided with a band generally designated 62 which is secured to the upstanding tubular wall 64- thereof. The purpose of the band 62 is to provide additional support for the wall 64. ln order to be relatively universal for different fibrous filters 60, the band 62 is provided with male and female snap portions 66 and 68, respectively. The band 62 is also provided with at least one longitudinally extending and inwardly directed lip 70; that is, in the assembled position, radially spaced from the main body of the band 62. The band is placed on the inside surface of the wall 64 and a suitable pair of fasteners 66 and 68 are selected and closed. The wall 64 is then curled over and into the lip 70 so as to secure the band 62 in place. As in the previous embodiment an O-ring is sewn into the flange of the filter medium 60 and coupling means are provided for joining the filter medium 60 and the filter basket 18.

A third embodiment of this invention is shown in FIGS. 7 and 8. The intermediate filter medium 80 in this embodiment is tubular in cross section and is attached to nestingly or telescopingly receive the filter basket 18. An O-ring 82 is sewn in the upper end of the filter medium 80 and thus provides the coupling means with the filter basket 84. The O-ring is stretched at assembly and is mounted onto a radially extending lip 86 formed integrally with the filter basket 84.

All of the embodiments of the intermediate filter comprise the present invention described hereinabove and exhibit the common characteristics of being coupled to the filter basket. Accordingly, each of the embodiments of this invention provides for the removal of the intermediate filter together with the filter basket. The construction hereinabove described provides a maximum of convenience together with improved filtering and longer life, for the main filter medium. Since the intermediate filter is removed together with the filter basket, it may be easily washed and easily replaced.

Having thus disclosed the best embodiment of the invention presently contemplated, it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention.

1 claim:

1. In a recirculating filter system for a swimming pool having a first filter through which at least a portion of the water in the pool is adapted to flow and a second filter through which all of the water in the pool is adapted to flow, the improvement comprising:

a. a third filter which is both porous and fibrous and which is positioned downstream of the first filter, said third filter being less porous than the first filter and more porous than the second filter, said third filter comprising a disc and an annular wall extending axially therefrom, said wall having a smaller outside diameter than said disc; and

b. means for spacedly coupling said third filter with respect to the first filter whereby the coupled filters are removable together as a unit, said third filter being readily severable from the first filter, said coupling means comprising an elongated flexible member secured at its opposed ends to the central portion of the first filter and to the central portion of said disc, said third filter being thereby axially spaced from the first filter.

2. The improvement in accordance with claim 1 including means for stiffening the sidewall of said cup-shaped third filter.

3. The improvement in accordance with claim 2 wherein said stiffening means is an elongated flexible band integral with the sidewall of said cup-shaped third filter.

4. The improvement in accordance with claim 3 wherein said flexible band includes means for varying the length thereof.

5. The improvement in accordance with claim 3 wherein said flexible band includes means for gripping the sidewall of said cup-shaped third filter.

6. In a recirculating filter system for a swimming pool having a tubular, first filter through the annular wall of which at least a portion of the water in the pool is adapted to flow and a second filter through which all of the water in the pool is adapted to flow, the improvement comprising:

a. a third filter which is both porous and fibrous and which is positioned downstream of the first filter, said third filter being less porous than the first filter and more porous than the second filter, said third filter being cup-shaped and having a base wall, an annular sidewall and a radially inward directed flange formed at the opposite open end thereof, the tubular first filter being nested within said cup-shaped third filter with one end thereof resting on said base wall of said third filter; and

b. means for spacedly coupling said third filter with respect to the first filter, whereby the coupled filters are removable together as a unit, said third filter being readily several severable from the first filter, said couple means comprising a resilient ring secured to said flange and arranged to releasably grip the opposite end of the first filter whereby said third filter sidewall is stretched taut and is radially spaced from the annular wall of the first filter. 

